Jun. 20—Companies of all sizes must bolster their cybersecurity defenses as emboldened hackers launch high-profile and costly ransomware attacks like those that hit Colonial Pipeline Co. and meatpacker JBS last month, according to local and national cybersecurity experts.

New hacking opportunities also opened during the pandemic when companies sent employees home to work on equipment that was less secure than in the office and as remote employees became more reliant on email, a common entry point for cyber intruders.